The role of ion translocations in the transduction of the hormonal message in the plasma membrane will be studied in the turkey erythrocyte which has an adenylate cyclase sensitive Beta-adrenergic catecholamine stimulation. Intact erythrocytes, resealed ghosts and permeable ghosts will be compared. Specific ion transport and its role in transduction will be evaluated with the use of ionophores and ion inhibitors as well as the use of impermeant for permeant ions. Concentrations of sodium, potassium, hydrogen, calcium and chloride will be determined. Ion fluxes will be determined with the appropriate radioactive isotope. Membrane potential will be determined with potential sensitive fluorescent probes. Rapid reaction kinetics spectrofluorimetry will be employed to evaluate alterations in membrane potential which occur in sub-second intervals. The effects of changes in specific ion transport on binding of catecholamine hormones, hormonal stimulation of cyclic AMP formation and membrane potential changes will be studied. All catecholamine responses will be performed in the presence and absence of alpha and beta-adrenergic inhibitors. On the basis of the kinetics of the various responses and varying stoichiometry, an attempt will be made to establish the sequence and the mechanisms of membrane reactions.